Heating apparatus.



G. MAGHLET, JR.

HEATING APPARATUS.

APPLICATION FILED AUG. 1, 1906. 1 099 658. Patented June 9,1914.

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I KQQ? Furnace.

WITNESSES:

Jig/KW v ATTORNEY G. MAGHLET, JR.

V HEATING APPARATUS. APPLICATION FILED AUG. I 1906. 1,099,658. Patented June 9,1914.

3 SHEETS-SHEET 2.

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WITNESSES: INVENTOR ATTORNEY G. MAGHLET, JR-

HEATING APPARATUS. APPLICATION FILED AUG. 1, 1906.

WITNESSES.

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GEORGE MACHLET, 33., OF ELIZABETH, NEW JERSEY.

HEATING APPARATUS.

Specification of Letters Patent.

a lication filed August 1, 1906. Serial No. 328,697.

To all whom, it may concern:

Be it known that I, GEORGE Maoxrnn'r, J n, a citizen of the United States, residing in Elizabeth, in the county of Union and State the maximum suppply of fuel to the furnace of New Jersey, have invented certain new and useful Improvements in Heating Apparatus, of which the following is a specification.

This invention relates to furnaces, such as used for heating metal and other articles for the purpose of annealing, hardening, etc., and also to furnaces for melting metal and other substances, and enerally to all furnaces in which it is desirable to secure and maintain-uniformly the precise degree of heat needed for the material in the. furnace or heater.

One of the principal objects of my invention is to reduce the difliculty of securing and maintaining the furnace heat at the desired point; Heretofore it has been n'eces sary for the attendant to watch a pyrometer and to regulate the flow of gas from time to time according to his judgment and experience, greatly exceeding or falling short of the desired point.

- -According to my invention the supply of fuel, whether gaseous or liquid or any other form, is regulated by the heat of the furnace itself. When the heat reaches a predetermined point, the supply of fuel is either reduced or cut off, and if the heat diminishes a trifle, the supply is renewed or increased so that the heat of'the furnace is maintained with substantial uniformity at the precise point desired, which is a matter of great importance in many arts. Moreover, it frequently happens the same furnace for heating the same or different metals or materials'to different degrees, and accordingly I provide means for predetermining the degree of heat at which the fuel supply shall be reduced or regulated. In practice, the furnace may be started, the heat controlling device maybe set to any desired degree, and the fuel will be supplied in maximum volumeuntil the furnace reaches substantially the precise degree of heat for which it has been set, whereupon the supply of fuel will be automatically reduced to prevent overheating and then increased to prevent underheating, so that the so as to prevent the heat from that it is desired to use heat is maintained uniformly at the point set.

The heat governing apparatus includes means for regulating both the minimum and according to the judgment of the attendant. For some furnaces and some kinds of work there should be little variation between maximum and minimum sup ly, whereas in other cases the supply shou d at times be very great and again shut completely off. All such variations are readily secured by my invention. It is also important, especially where fuel gas and air are mixed .before entering the burners in the furnace, to secure the right proportion of. the gas to the air, and accordingly one feature of my invention resides in securing any desired proportion and causing such proportionto be maintained in uniformity during all fluctuations in the volume of the "mixture supplied to the furnace.

. In the preferred form of the'invention, there is employed an apparatus for regulating or controlling the proportions of gas.

and air to be supplied to the furnace, and this apparatus includes a single valve having an air port and a gas port, sothat when the valve is operated, both the ports are opened or closed in unison. The valve is operated or controlled by means of a solenoid included in an electrical circuit which is controlled by the heat of the furnace, this being done by means of a pyrom'eter having a movable part for indicating the heat, and means cooperating with such movable part for opening and closing the circuit in which said magnet is included. The opening movement of the valve is limited by an adjustable stop, whereby the manimum supply Patented J nne 9, 1914.

of air and fuel to the furnace is determined;

and another adjustable stop is provided for limiting the closing movement of said valve so that the latter may either partly close or close altogether, when the desired degree of heat of the furnace is attained, according to the character of the furnace and work in hand. A closure is provided for the gas port in said valve, which is operableinde- I pendently of the air port, and the movement,

of said closure is directly tion of gas may be decreased or increased transverse to the movement of the valve, whereby the :propon independently of the opening and closing movements of the valve, thus securing during all fluctuations in the volume of mixture supplied to the furnace any desired proportions of gas and air.

Other features and advantages will hereinafter appear.

In the accompanying drawings, Figure 1 is a diagrammatic elevation of a gas furnace and an apparatus for controlling .the heat thereof. Fig. 2 is a plan, and Fig. 3 a side elevation partly in section of a voltmeter forming part of a pyrometer, and also having means to control the supply of fuel to the furnace. Fig. 4 shows a vertical central section of an apparatus for controlling the proportions of gas and air. Figs. 5 and 6 are cross-sections of the lower part' of the valve and shell, Fig. 5 showing the gas ports open, and Fig. 6 showing them closed by means of a manually adjustable closure. Fig. 7 is a vertical central section through the mixture regulating apparatus taken at right angles to the Fig. 4 section. Fig. 8 shows an air shell or tube fixed in the upper part of the mixture regulator or proportion adjuster. Fig. 9 shows a tube which is mounted in the lower part of the mixture regulator for rotation to serve as a closure for the gas ports and the main valve. Fig. 10 shows the main valve in the regulator. Fig. 11 is a sectionaLview of an air operated diaphragm for opening the valve in the regulator, and a magnetically operated valve for controlling the flow of compressed air to and away from said diaphragm. This figure illustrates the preferred means for operating the valve seen at Figs. 4 to 10. In the form seen at Fig. 4, the core of a solenoid is attached directly to said valve. Fig. 12 shows a cross-section of a tube, showing vents for the exhausting of air from and admission of air to said diaphragm. Fig. 13 is an enlarged sectional view of parts seen at Fig. 11 for controlling the flow of air from the oration of said diaphragm. flliig. 14 is a plan of the apparatus seen at The fuel-gas enters through a pipe 1, and the air to be mixed therewith enters through a pipe 2, theair being usually supplied under pressure of a pound to several pounds to the inch. 'Air and gas pass separately through a proportion-adjusting apparatus 3, the gas flowing therefrom through a plpe 4, and the air through a pipe 5. The pipe 4 joins pipe 5 at the point 6, and the mixture flows through pipes 7, 8 and 9 to burners 10 which enter a furnace 11.

The apparatus 3is in the form of a vertical pipe cast with suitable nipples to receive the pipes 1, 2, 4, 5, and divided by partitions 12, 13, 14 into four chambers, namely, air inlet chamber 15, air olitlet chamber 16, gas inlet chamber 17 and gas outlet chamber 18. A main valve in the form of a vertical tube 19, Fig. 10, extends through said apparatus 3, said valve passing through all of said partitions and being itself divided by a partition 20 into an upper compartment 21 for air, and a lower compartment 22 for gas. The compartment 21 in the valve afi'ords a passage for air between the inlet and outlet chambers 15 and 16. The compartment 22 forms a similar passage for gas between the inlet and outlet chambers 17 and 18.

Fixed in the upper part of the regulator or proportion adjuster is a tube or shell 23, Fig. 8, extending through the chambers 15 and 16, and having opposite openings 24 in the former and opposite openings 25 in the latter. The openings 24 register with opposite openings 26 in the valve, and the openings 25 are also juxtaposed to opposite ports 27 in the valve. It will be understood that the openings are made oppositely in the valve partly for balancing the same and partly to secure ample passages for the. fluids. The valve is seen closed at Fig. 4, the portions of the shell 23 indicated in dotted lines at 28, Fig. 8, serving as closures, for the.

ports 27. When thevalve is fully raised, said ports register with the openings 25 in the shell 23, thereby establishing free communication between inlet and outlet pipes 2 and 5. The passages 24 and 26 are always open, the latter being of the greater height so as to compensate for the vertical movement of the valve. In the lower end of the device is inserted another shell or tube 29 opening at its upper end into the gas inlet chamber 17, and extending through the gas outlet chamber 18in which it has opposite openings 30. The valve 19 extends also through tube 29, and fits closely in both tubes 29 and 23 while free to move up and down independently thereof. Near the lower end the valve is provided with opposite ports 31, which when the valve is lifted register with the passages 30 in the tube 29. The portion of the latter indicated by dotted lines 32, Fig. 9 just' below the openings 30 serves as a closure for the ports 31 when the valve is dropped, Fig. 4. The valve has opposite openings 33 in the gas inlet chamber 17 corresponding with the openings 26, said openings 33 being never closed. In the bottom of the valve is fitted a plug 34, and a central pipe 35 opens at one end through the plug and at the other end through the partition 20 to admit com-- pressed air beneath the plug 34 to facilitate lifting the valve. The valve is lifted by means of a rod 36, which is caught at its lower end upon a long transverse pin 37 thrust through a head 38 provided in the valve and also extending through the opposite slots 39 formed in an extension of the tube 23, which projects above chest 3. An

opening 36 in the top 36" of head 38, presents a vacuum forming above the head. Upon said extension are threaded nuts 41 and 42,. one above and one below the pin 37 and engageable thereby, so that the nuts serve as adjustable stops to limit the opening and closing movements of the valve.' In

the Fig. 4 construction, the rod 36 constitutes the core of a solenoid 43, whereby the valve 19 is lifted; but in the preferred form of the invention, Fig. 11, said rod is attached at its upper end to a flexible diaphragm 44 provided in a frame or casing 45. The upper end of the extension 40 is screwed into said casing at 46.

Compressed air is admitted from the pipe 2 to the casing 45, that is to the lower chamber 47 of the two into which said casing is divided by said diaphragm 44; the upper chamber having a vent 48. A small solenoid 49 controls the flow of compressed air from the supply pipe 2 to the chamber 47, as well as the venting of air from said chamber. The core 50 of the solenoid 49 is formed at its lower end with a head which constitutes'a valve 51 fittingin a stationary tube 52 and resting upon a seat 53, thereby closing said tube when the core is down. For convenience in manufacture, said tube 52 is inserted in a block or length of thick pipe 54 upon the top of which the solenoid 49 is secured, and a pipe 55 leads from said tube 'to the diaphragm chamber 47. When the valve 51 is lifted, the air passes up from the supplypipe 2 into the lower end of the tube 52 and through holes 56 in the side ofthe latter above the seat 53; but when the valve drops, the tube 52 is completely closed below said hole 56, while, owing to the thinnessof the valve 51, the hole 56 is left open at the top, (Fig. 13,) to permit air to vent from the chamber 47 through vents 57 formed in said tube, the corebeing cut away at 58 to form a passage in the tube between'the holes 56 and vent or vents 57. When the valve is raised, the head 51 is lifted up above the balanced holes 56, and no air escapes through said vents. The tube 52 may continue up to form the central part of the framework of the solenoid as illustrated, and to serve as a guide for the upper end of the core. 7 i

It will be seen that when the solenoid is energized, the core, is raised, thus closing the tube 52 above the port 56 and leaving an open passage through said port from the compressed air supply 2 to the diaphragm' chamber 47. The diaphragm is raised by the" air'pressure, .thus liftingthe valve 19 and opening the ports 27 and 31, so that air and gas flow simultaneously through the chest 3. The extent to'whichthe valve opens depends upon the adjustment of the stop 41. When the; magnet is deenergized, the solenoid drops and the valve 51 closes the tube 52below the port 56 and permits the air to escape from the chamber 47 through the vents.57, whereupon the valve 19 drops until arrested by the adjustable nut stop 42. The solenoid 49 is included in a circuit designated generally as 59 and including a battery or other source of electro-motive force 60, and also including a switch 61 normally held closed by a spring 62. Said circuit also includes a fixed metal bracket 63 having a lip 64 against which said switch closes. It will be seen that the electricity may flow from the battery through the wire 59, then through the solenoid 49, a wire 59*, the switch 61, the bracket 63, and a wire 59", back to the battery, and that while the circuit is closed, the valve 51 is lifted, and the regulating valve 19 is opened, so that air and fuel are supplied to the furnace.

The means for controlling the fuel supply also includes a thermo-elect-ric generator 65, which is usually termed an element, and is of well known form, and is inserted directly in the heat chamber of the furnace. This generator is included in an electrical circuit 66, Fig. 1, which also includes a volt- I meter or device 67 for indicating the flow of electricity 'in said circuit 66; said voltmeter usually including a movable coil 68,- to which is fixed an index arm 69 to cooperate with a scale 70. When the element isheated, the electricity flows through the circuit-'66, and the coil 68 turns, thus moving the index 69 along the scale 70 to an extent. to determine the degree of heat in the furnace. The scale may show either the heat ofthe furnace or the power of the electric current or both. I utilize the movement of said coil 68 to control the valve operating circuit 59. For this purpose another circuit 7l-is provided including a wire 72, which is mounted on said index arm 69, and leads to a contact 73 provided upon the tip of said arm. In the path of saidcontact is provided a coiiperating contact 74, upon the end of a metal arm 75, which is pivoted at 76 concentrically with the pin 77, upon and with which turns the member or wires 68 of the voltmeter, the'pin being delicately poised upon a seat 7 7 scale 70 and rigidly secured by a nut 78'. When the arm 69 swings to the right sufliclently to engage the'contacts 73 and 74,

the circuit 71 is closed, and the switch 61 is opened by means of a magnet 79 which is included in said circuit 71. It will be seen that beginning at contact 73, the current 82 of the voltmeter or galvanometer, said The contact '74 may hence be set at any point on the bracket being connected to a post 83 to which is secured the wire 71. The latter leads through the magnet 79, and thence through the wires 71 and 59 to-the battery 60, the circuit including a wire '79" connected to the conductor arm 75. The opening of the switch 61 breaks the solenoid circuit 59, thereby reducing or stopping the flow of fuel to the furnace according to the adjustment of the stop 42. The wire 72 is very fine and light, and afi'ords no appreciable resistance to the movement of the index arm 69, which is delicately poised, and which must indicate accurately the flow of electricity in the circuit 66. In order to avoid injury to the fine Wire 72, the coil I 79 of the magnet 79 may be made of resistance wire, so that the whole energy of the battery 60 shall not flow through said wire 72.

In operation it being assumed that the current is flowing through the circuit 59, valves 84 and 85 in the gas and air supply pipes 1 and 2 are opened. Compressed air flows from pipe 2 through the tubes 52 and 55 to the chamber 47, and lifts the diaphragm 44, thereby raising the valve 19 so that gas and air may flow therethrough and thence through the pipes 4, 5 and 7 to the furnace burner system 8, 9, 10, the gas being ignited within the furnace. The heating of the element or thermo-electric generator 65 causes the current to traverse the circuit 66 and the member 68 to turn. The arm 75 is swung around to the point on the scale 70 which indicates the degree of heat which it is desired to secure and maintain in the furnace. As the furnace grows hotter, the arm 69 gradually approaches the arm until the cont-act 73 engages the contact 74, thereby closing the circuit 71 and breaking the circuit 59 at 61, whereupon the solenoid 49 is deenergized, its core drops, closing the passage bet-ween the compressed air supply .2 and diaphragm chamber 47, and permitting the air to vent from the latter. so that the diaphragm drops together with the valve 19, thereby partly or wholly closing the air and gas ports in the chest 3. The flames in the furnace being hence reduced or extinguished, the furnace begins to cool, thus reducing the current flowing in the voltmeter, whereupon the armature 68 begins to turn backand the contacts 73 and 74 are separated and the circuit 71 broken. The spring 62 closes the switch 61, thereby permitting the current to flow through the circuit 59 and the solenoid 49, so that the valve 19 is opened and air and gas again flow into the furnace, which is now suflicient-ly hot to ignite the-gas. It willbe understood however, that the stop 42 may be adjusted if desired so as to permit a little gas to flow into the furnace, so that the flames may not entirely die out when valve 19 drops. 5 After the contacts 73 and 74 engage, a very slight reduction in the heat of the furnace is suflicient to separate them, .and thereby renew the supply of fuel, so that the fluctuations in the temperature of the 70 furnace when in operation are very slight. The attendant adjusts the stops 41 and 42 to limit the opening and closing movements of the valve according to the heat required and the work in hand, and also turns a hand 75 wheel 86 to rotate the shell or sleeve 29 to open or close the gas ports 31 in the valve 19, thereby securing the desired proportions of gas and air in the mixture, which are required for different kinds of work. It will be seen that the adjustment of the sleeve 29 is at right angles or transverse to the opening or closing movements of the valve, whereby the passage at 31 may be enlarged or diminished transversely to alter the flow of gas, while remaining of the same height as the air port 27,. so as to be co-extensively opened or closed by the movements of the valve 19. In this way, any desired proportions of gas and air are constantly maintained throughout all'fluctuations in the volume ofthe mixture delivered to the furnace.

The hand wheel 86 may be provided with an index 87 to cooperate with a-scale 88 to inform the attendant to what extent the passage 31 is opened or closedby the sleeve 29. The plug 89 is secured by a screw 90 in the bottom end of the sleeve 29, and the wheel 86 is secured upon the stem of the plug by means of a pin 91, which carries the index 87. The scale 88 may be formed upon a screw cap threaded upon the bottom of the chest 3 and provided with a locking screw 90. The judgment and experience of the attendant will dictate the extent to which to turn the hand wheel 86 for different classes or work, and will also enable him to set the stops 41 and 42 properly; whereupon the furnace will maintain the heat at the desired point for an indefinite length of time without further attention.

Many variations may be resorted to within the scope of the invention, as for instance the solenoid 43, Fig. 4, may be connected in the circuit 59, thus dispensing with the diaphragm 44 and its casing, as well as with the solenoid 49, andits appurtenances. It is not necessary in all cases to use every part of my novel features of invention, as for instance the index 87 and other subordinate features-may be omitted.

Pending application No. 432,341, filed May 12, 1908, is a division of this applica ton, and covers only the mixing valve and chest herein illustrated, the valve-operating parts, and the adjustable mechanism at or in the valve chest. All of the claims in this application include the furnace or device to which the mixture of gas and air is delivered for consumption.

Having thus described my invention, I claim:

1. In combination, a chest provided with means for passing fuel gas and air unmixed therethrough, a valve in said chest, said valve being provided with means for proportionately'\increasing or diminishing the flow of air and gas simultaneously, a mixing device, a combustion device, means for conveying the mixed air and gas from the mix- 7 ing device to'the combustion device, a pyrometer mechanism comprising a movable element indicating the heat of the furnace, and a cooperating part in thermal relation to said combustion device and connected to said valve, for opening and closing the said valve, and adjustable stops for limiting both opening and closing movements of said valve.

2. In combination, a chest provided with means for passing fuel gas and air unmixed therethrough, a valve in said chest, said valve having means inclusive of air and gas ports, for proportionately increasing or diminishing the flow of gas and air simultaneously, a mixing device in communication with said chest, a heating device, a connection between said mixing device and said heating device through which the mixed gas and air are delivered, a pyrometer mechanism comprising a movable element indicating the heat of the furnace, and a cooperating part in thermal relation to said heating device, connections between said pyrometer mechanism and said valve for opening and closing the latter, and a manually adjustable closure for one of said ports, said closure adjustable in a direction transverse to the movement of said valve for varying the proportion of air and gas in the mixture.

3. In combination, a chest having provision for receiving and delivering fuel gas and air, a valve in said chest and divided into air and gas compartments and having a port in each compartment for the passage of the fluid, a casing containing a diaphragm connected to said valve for moving the latter, means for supplying compressed air to said chest, a tube forming a passage between said casing and said air supplying means, said tube having a port for the passage of air and also having a vent, a solenoid having a core movable up and down in said tube, the lower end of said core fitting said tube and forming a valve to close said port, and said core being cut away to form a passage from said port to said vent, so as to vent air from said casing when said port is closed against the admission of compressed air to said casing, an electric circuit of which said solenoid forms a part, and means for controlling said circuit.-

4. In combination, a furnace for burning mixed gas and air, a mixing device, means connecting said mixing device to said furnace, a controller for controlling the sup-- ply of gas and air, means connecting said controller to the mixing device, said controller having a valve provided with separate gas and air ports for passing fuel gas and air unmixed thereto, a pyrometer mechanism comprising a movable element indicating the heat of the furnace, and a cooperating part extending from the furnace to the valve, and means whereby the pyrometeris arranged in controlling relation to said valve, and adjustable stops for limiting the opening and closing movement of said valve.

5. In combination, a furnace for burning mixed gas and air, a mixing device for said gas and air, connections between said mixing device and said furnace, a controllin device for controlling the supply of gas an air, connections between said controlling device and said mixing device, said controlling device having a valve provided with separate gas and air ports for passing fuel gas and air unmixed through said valve, a pyrometer mechanism comprising a movable element indicating the heat of the furnace, and a cooperating part extending from the furnace to the valve, said pyrometer mechanism being arranged in controlling relation to said valve, whereby the valve may close or open as the temperature in the furnace rises and falls, and means for opening or closing one of said gas and air ports independently of the others for varying the preportions of gas and air delivered to the furnace.

6. In combination, a furnace for burning mixed gas and air, a gas and air proportion adjuster connected to the furnace and having a valve provided with separate gas and air ports, means dependent upon the heat in the furnace for opening and closing said valve, means for opening orclosing one of said ports independently of the other for varying the proportions of gas and air delivered to the furnace, and adjustable stops for limiting the opening and closing movements 'of said valve.

7. In combination, a furnace for mixed air and fuel gas, an electric circuit including a thermo-electric generator at said furnace, and also including a device movable by the current in said circuit, a single mixing valve controlled by said movable device for decreasing the supply of mixed air and fuel to said. furnace when its heat becomes excessive and increasing such supply when the heat becomes inadequate, and means for manually regulating the extent of throw of said valve.

8. In combination, a furnace for mixed air and fuel gas, an electric circuit including a thermo-electric generator in said furnace, and also including a device movable by the current in said circuit, a second electric circuit closable by said movable device, a mixing valve controlled by said second circuit, and means controlled through said valve for decreasing the supply of air and fuel to the furnace when its heat becomes excessive and increasing such supply when the heat becomes inadequate, and means for manually regulating the extent of throw of said valve.

9. In combination, a furnace for mixed air and fuel gas, an air and fuel proportion adjuster including a valve, a magnet for effecting the opening of said valve, an electric circuit including said magnet and also including a source of electro-motive force, and means dependent upon increase of the heat of the furnace to a predetermined point for breaking sald circuit and causing a closing of said valve to effect a substantial reduction in the supply of fuel, and air simul taneously.

10. In combination, a furnace for mixed air and fuel gas, an air and fuel proportion adjuster including a valve, a magnet for operating said valve, an electric circuit including said magnet and also including a source of electro motive force, a normally open circuit having means to breaksaid magnet circuit, and means dependent upon increase of the heat of the furnace to a predetermined point for closing said normally open circuit, and causing a closing of said valve to effect a substantial reduction in the supply of fuel,

, and air simultaneously.

11. In combination, a furnace for mixed air'and fuel gas, an air and fuel proportion adjuster including a valve, a magnet for op erating said valve, an electric circuit including said magnet and also including a source of electro-motive force, a normally open cir cuit having means to break said magnet cir cuit, and an electric circuit including a thermo-electric generator at said furnace, and also including a part movable by the current and having means to close said normally open circuit, and cause a closingof said valve to effect a substantial reduction in the supply of fuel, and air simultaneously.

12. In combination, a furnace for burning mixed fuel-gas and air, a valve for controlling the supply of gas and air to said furnace, a normally closed electric circuit including a source of power, and also including a magnet having means to operate said valve, a normally open circuit having means to break said magnet circuit, and a circuit including a thermo-electric generator in said furnace, and also including a voltmeter whose movable member has a contact for closing said second circuit. and causing a closing of said valve to effect a substantial reduction in the supply of fuel, and air simultaneously.

13. The combination of a furnace for mixed air and fuel gas, a valve connected thereto for mixing air and fuel, an electric circuit including a thermo-electric generator in said furnace, and also including a voltmeter having a movable part, means for enabling said movable part to control the supply of fluid fuel to the furnace, and including a member in the path of said movable part and adjustable relatively thereto for cooperating with said movable part to control said mixing valve to effect reduction of the supply of fuel and air simultaneously to the furnace upon the heat of the latter increasing to the predetermined point, and means for manually regulating the extent of throw of said valve,

14.. In combination, a furnace for burning mixed fuel-gas and air, means, including a mixing valve, for mixing the gas and air and supplying the mixture to the furnace, and mechanism, including a device regulated by the heat in the furnace and extending from the furnace to the mixing valve, to control the supply of gas and air to the mixing means and hence the supply of the mixture to the furnace, for maintaining uniformly a predetermined degree of heat in the furnace; said controlling means including a member which may be adjusted to determine the point at which the supply of fuel and air to the furnace shall be reduced simultaneously; and means for manually regulating theextent of throw of said valve.

15. In combination, a furnace for mixed air and fuel-gas, a valve connected thereto for mixing air and fuel, an electric circuit including a thermo-electric, generator at said furnace, and also including a device movable by the current in said circuit, a second circuit normally open and including said movable device, and also including a contact in the path of said movable device,

said contact mounted for adjustment to close the circuit earlier or later in the operation of said movable device, means controlled by said second circuit to control said valve for causing the supply of fuel-gas and air' to the furnace to be reduced simultaneously upon the heat of the latter increasing to the predetermined point; and means for manually regulating the extent of throw of said valve. a

16. In combination, a furnace for mixed air and fuel-gas, a valve having means for increasing or diminishing the supply to the .furnace of air and fuel-gas simultaneously,

said valve including a manually operable fuel-adjuster, a magnet for operating said valve, an electric circuit including said magnet and also including a source of electro-motive force, and means rendered effective upon the lncrease of the heat of the furnace to a predetermined point for breaking said circuit, and including a device which is adjustable to predetermine the degree of heat in the furnace at which the circuit shall be broken.

17. In combination, a furnace for mixed air and fuel-gas, a valve having means for increasing or diminishing the supply to the furnace of air and fuel-gas simultaneously, said valve including a manually operable fuel-adjuster, a magnet for opening said valve, an electric circuit including said 'magnet and also including a source of electromotive force, a normally open circuit having means to break said magnet circuit and close the valve, and means rendered effective upon the increase of the heat of the furnace to a predetermined degree, for closing said normally open circuit; the latter including cooperating contacts one of which is adjustable, and the other of which is operated to an extent dependent upon the degree of heat in the furnace.

18. In combination, a furnace for mixed air and fuel-gas, a valve having means for increasing or' diminishing the supply to the furnace of air and fuel-gas simultaneously, said valve including a manually operable fuel-adjuster .a magnet for opening said valve, an elec ric circuit including said magnet and also including a source of. electromotive force,a normally open circuit having means to break said magnet circuit and close the valve, and an electric circuit including a thermo-electric generator at said furnace,

and also including a part movable by the current and carrying a contact which is included in said open circuit, the latter having a cooperating contact which is adjustable to determine the degree of heat in the furnace at which said contact shall engage to close 'said open circuit.

19. In combination, a furnace for mixed air and fuel-gas, a valve having means for increasing or diminishing the supply to the furnace of air and fuel-gas simultaneously, said valve including a manually operable fuel-adjuster, a normally closed electric circuit including a source of electro-motive force, and also including a magnet having means to open said valve, anormally open circuit having means to break said magnet circuit and close the valve, and a circuit including a thermo-electric generator in said furnace, and also including a voltmeter whose movable member'has a contact for cooperation with a contact in-said open circuit, the last-mentioned contact being adjustable to determine the degree of heat in the furnace at which said contact shall engage.

O. In comblnation, a furnace for burnclosed velectric circuit including a source of electro-motive force, and also including a magnet having means to open said' valve, a normally open circuit having means to break said magnet circuit and close the valve, and a circuit including a thermo-electric generator in said furnace, and also including a voltmeter whose movable member has a contact for cooperation with a contact in said open circuit, the last-mentioned contact being adjustable to determine the deee of heat in the furnace at which said contact shall engage; means dependent upon the separation of said contacts being provided for closing the first-mentioned circuit.

21. In combination a furnace, a valve for controlling the sup 1 y of fuel to said furnace, a normally 0 osed electric circuit including a source of electro-motive force, a magnet to control said valve, a switch having a spring to keep it closed, a second circuit also including said source of electromotive force, and including a magnet to open said switch and break the first circuit, and a third circuit including an electric thermo-generator in said furnace, and also including a voltmeter whose movable member carries a contact belonging to the second circuit, and a cooperating contact in said second circuit, and adjustable in the path of said movable contact for determining the degree of heat at which said second circuit shall be closed and the first circuit broken.

22. In combination, a furnace, a valve for controlling the supply of fuel to said furnace, a normally c osed electric circuit including a source of electro-motive force, a magnet to control said valve, and a switch having a spring to keep it closed, a second shall be closed and the first circuit broken;

a resistance being provided in the second circuit.

23. In combination, a furnace, a valve for controlling the supply of fuel to said furnace, a normally closed electric circuit including a source of electro-motive force, a magnet to control said valve, and a switch its having a spring to keep it closed, a second circuit also including said source of electromotive force, and including a magnet to open said switch and break the first circuit, and a third circuit including an electric thermo-generator in said furnace, and also including a voltmeter whose movable member carries a contact belonging to the second circuit, and a cooperating contact in said second circuit, and adjustable in the path of said movable contact for determining the degree of heat at which said second circuit shall be closed and the first circuit broken; said movable member of the voltmeter being pivoted and comprising an index arm having the contact, said adjustable contact being also in the form of an index arm pivoted concentrically with the firstmentioned index arm, and having means to secure it where adjusted.

24. The combination with a furnace 'for mixed air and fuel-gas, of a mixing valve, a pyrometer having a movable device for indicating the heat of the furnace, means including a part to cooperate With said movable device and adjustable relatively thereto to cooperate with said valve for reducing the supply of fuel-gas and air to the furnace simultaneously upon the heat of the furnace increasing to the predetermined point; and means for manually regulating the extent of throw of said valve.

25. The combination with a furnace for mixed fluid-fuel and air, of a voltmeter connected to a pyrometer in said furnace, a mixing valve controlling the supply of both fuel and air to the furnace and connected to said voltmeter to be closed thereby to reduce the flames of the furnace but incapable of quenching said flames through the action of said voltmeter, and means for manually regulating the extent of throw of said valve.

26. The combination with a furnace for mixed fluid-fuel and air, of a voltmeter connected to a pyrometer in said furnace, and a mixing valve controlling the supply of both fuel and air to the furnace and connected to said voltmeter to be closed thereby to reduce the flames of the furnace but incapable of quenching said. flames through the action of said voltmeter, manually adjustable means being provided to regulate the extent to which the valve may be opened by said voltmeter.

27. The combination with a furnace for burning mixed fluid-fuel and air, of a volt-.

meter connectedto an element in said furnace, a device for adjusting the proportions of fuel and air supplied to said furnace, and having means for admitting the gas and air and delivering it to said furnace, and means controlled by said voltmeter for controlling the volume of gas and air delivered by said adjusting device.

28. The combination with a furnace for burning mixed fluid-fuel and air, of a voltmeter connected to an element in said furnace, a device for adjusting the proportions of fuel and air supplied to said furnace, and

55 having means for admitting the gas and air and delivering it to said furnace, and means controlled by said voltmeter for controlling the volume of gas and air delivered by, said adjusting device, said volume-controlling means including mechanism for securing unvarying proportions of fuel and air during the fluctuations of the volume delivered.

29. The combination with a furnace for burning mixed fluid-fuel and air, of a voltmeter connected to an element in said furnace, a device for adjusting the proportions of fuel and air supplied to said furnace, and having means for admitting the gas and air and delivering it to said furnace, means controlled by said voltmeter for controlling the volume of gas and air delivered by said adjusting device, said volume-controlling means including mechanism for securing unvarying proportions of fuel and air during the fluctuations of the volume delivered, and manually adjustable means for regulating proportions of fuel and air in the mixture delivered to the furnace.

30. The combination with a furnace for burning mixed fuel gas and air, of a voltmeter connected to an element in said furnace, an apparatus for adjusting the proportionsof fuel-gas and air delivered to the furnace and having a chest provided with separate air. and gas admitting means and separate air and gas delivering means, a hollow valve extending through said'chest and having air inlet and air outlet ports and also having gas inlet and gas outlet ports, a mechanism to control said Valve, said controlling mechanism under control of said voltmeter, to cause the valve to effect corresponding variations in-the volumes of air and gas flowing therethrough, and means for independently. regulating the proportions of gas and air inthe mixture delivered.

31. The combination with a furnace for burning mixed fuel gas and air, of a voltmeter connected to an element in said furnace, an apparatus for adjusting the proportions of fuel-gas and air delivered to the furnace and having a chest provided with separate air and gas admitting means and separate air and gas delivering means, a hollow valve extending through saidchest and hav ng air inlet and air outlet ports and also having gas inlet and gas outlet ports, a mechanism tojcontrol said-valve, said controlling mechanism under control of said voltmeter, to cause the valve to etl'ectv corresponding variations in the volumes of air and gas flowing therethrough, means for independently regulating the proportions of gas and air in the mixture delivered, and

- adjustable means to limit the opening movenace, an apparatus for adjusting the proportions of fuel-gas and air delivered to the furnace and having a chest provided with separate air and gas admitting means and separate air and gas delivering means, a hollow valve extending through said chest and having air inlet and air outlet ports and also. having gas inlet and gas outlet ports, a mechanism to control said valve,

said controlling mechanism under control of said voltmeter, to cause the valve to effectcorresponding variations in the volumes of air and gas flowing therethrough, means for independently regulating the proportions of gas and air in the mixture delivered, and adjustable means to limit the opening and closing movements of the valve.

The combination with a furnace for burning mixed fuel-gas and air, of a voltmeter connected to an element in said furnace, an apparatus for adjusting the proportions of fuel-gas and air, comprising a clzest constructed to admit and deliver gas and air, a hollow valve extending through said chest and divided into air and gas compartments, ports being provided in said compartments, and meansbeing provided for causing air and gas admitted to said chest to pass separately through their respcctive compartments in said valve, a tube or shell fitting said valve and having a port juxtaposed to one of the orts in said valve,

means for effecting relat ve adjustment between said valve and said shell to open or close the last-mentioned valve port independently of the. other valve port, so as to regulate the proportion of gas and air in the mixture delivered, and means cooperating with said valve and including said voltmeter to open or close its ports simultaneously, independently of said adjustment of the proportion-regulating means.

34. The combination with a furnace for burning mixed fuel'gas and air, of a. voltmeter connected to an element in said furnace, a chest having air-inlet and air-outlet chambers, and also having gas-inlet and gasoutlet chambers. all of said chambers being separate, a tubular valve extending through said chambers and divided into air and gas compartments, the air compartment having a port and being in communication wlth said air-inlet and said air-outlet chambers, and the gas compartment also having a port and forming a communication between the gas-inlet and gas-outlet chambers, a closure for said gas port, a closure for said air port, means for moving said valve to close both its ports simultaneously, means for adjusting the gas-port closure in a direction trans-- verse to the movement of the valve. so as to open or close the gas port and regulate the proportion of gas to air in the delivered mixture. and means cotiperating with said valve and including said voltmeter to open or close its ports simultaneously, independently of said adjustment of the proportionregulating means.

35. The combination with a furnace for burning mixed fuel-gas and air, of a volt-- meter connected to an element in said furnace, an apparatus for adjusting the proportions of fuel-gas and air, comprising a valve having an air port and a gas port, means for moving the valve to close or open both ports together, means adjustable in a direction transverse to the movement of the valve, for

closing or o ening one of saidports independently o the other thereof, so as to regu- 7 chamber, an air-outlet chamber, gas inlet and out-let chambers, a tubular valve extend ing throughsaid chambers and divided into air and gas compartments, and forming a communication between the air inlet and out let chambers, and also formin a communication between the gas inlet an outlet chambers, said valve having air and gas ports, closures in said air and gas chambers for said ports, means for moving said-valve end Wise 'to close or open said ports together, means for effecting rotative adjustment of the closure in the gas chamber, to vary the proportion of gas and air, and means cooperating with said valve and including said voltmeter to open or close its ports simultaneously, independently of said adjustment of the proportion-regulating means.

37. The combination with a furnace for burning mixed fuel-gas and air, of a volt-- meter connected to an element in said furnace, an apparatus for adjusting the proportions of fuel-gas and air, comprising a chest to receive and deliver the gas and air, a movable valve having means to increase or diminish simultaneously the flow of gas and air through the chest, adjustable stops for limiting the stroke of the valve in both directions, and means cooperating with said valve and including said voltmeter to open or close its ports simultaneously, independently of said adjustment of the proportionregulating means.

38. The combination with a furnacefor burning mixed fuel-gas and air, of a voltmeter connected to an element in said furnace, an apparatus for adjusting the proportions of fuel-gas and air, comprising a chest, a movable valve therein and provided with means for increasing or diminishing the flow of gas and air simultaneously, adjust- 'able stops for limiting both opening and closing movements of said valve, adjustable means for varying the proportion of gas and air delivered by the apparatus, and means cooperating with said valve and including said voltmeter to open or close its ports simultaneously, independently of said adjustment of the proportion-regulating means.

39. In combination, a chest having provision for receiving and delivering fuel-gas and air, a valve in said chest and divided into air and gas compartments and having a port in each compartment for the passage of the fluid, a casing containing a diaphragm connected to said valve for moving the latter, means for supplying compressed air to both said chest and said casing, a second valve controlling the admission of air to said casing and the exhaust of air therefrom, a furnace to which the proportioned gas and air are supplied, a pyrometer in said furnace, and means controlled by said pyrometer for controlling the movements of the second valve.

40. In combination, a chest having provision for receiving and delivering fuel-gas and air, a valve in said chest and divided into air and gas compartments and having a port in each compartment for the passage of the fluid, a casing containing a diaphragm connected to said valve for moving the latter, means for supplying compressed air to said chest, a tube forming a passage between said casing and said supplying means, said tube having a port for the passage of air, a valve in said tube for closing and opening said port, said tube having a vent, and said valve being constructed to open said vent When closing said port, a furnace to which the proportioned gas and air are supplied, a pyrometer in said furnace, and means'controlled by said pyrometer for controlling the movements of the second valve.

41. In combination, a chest provided with connected ingress and egress means for air and similar mcans for gas, a valve in said chest arranged to control simultaneously and proportionately the passage of air and gas through the chest, a mixing device in communication therewith, a burning device in communication with the mixing device, and a pyrometer in thermal relation to said burning device, said pyrometer being arranged to control said valve so as to furnish a proportioned flow of air and gas to said burning device whereby said flow is in the constant control of a determined developed temperature.

GEORGE MACHLET, JR. Witnesses:

SAMUEL R. OGDEN, ADOLPH W. lvlacm'r. 

